Hi all.

'99 SR5. 300k. With fair bits of aftermarket wiring.
I searched the threads and forums, and found a number of posts reporting this same problem, but could not find any mention of a definitely solution. So here it goes again, hoping that this will help me and others.

Situation:
Started last year, after heavy rains, door locks would begin to lock and unlock by themselves for hours at a time. Doesn't mater what position the ignition switch is on, if I'm in the car, engine running, or parked, with everything off. Once everything dried off, this would eventually stop.

Always attributed this to the actuator getting wet through aging/shrinking window seals. But now it's doing it on bone-dry days as well.

People have posted about the heat messing with the actual motor, which can be replaced. But this is a different symptom (I have the heat issue too), but this ghost shifting is not heat-related.

Some folks have talked about the fuse block needing to get replaced.

Others have mentioned the actuators needing replacement. But no definite solution has been posted.

Worn wires in the trunk and door rubber boot have also been mentioned (and I checked), but this is a very intermittent problem in my case.

Today as it was acting up, I could also hear a relay clicking from near the fuse block. This makes me think the faulty signals are originating there. When I put my hand on the bottom of the fuse block on the main harness, I could feel the clicking. After pushing around on that harness (see attached pic), it felt like it stopped for a few minutes, before it began again. This might have been coincidence.

Looking forward to hearing any related experiences and solutions. Thanks all!

Attached Images

 

Mined did that when a swapped doors. I had to bend the lock rod to get it to stop.

Being your noticing it more when it raining. That's more sounding like an electrical issue. So wires, switches and assemblies would be more the culprit.

Wire wise, your driver and rear door hatch could have a broken wire that didn't crack the insulation yet and acting up.

The late models [01 and 02] are more digital then analog. So this one maybe a process of elimination...

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Thanks @Briilo.

How did you come to the conclusion that the lock rod was the culprit?

That was my initial instinct too. I opened the door, there was some moisture in there, and I dried and taped the actuator off. But today it acted up in bone-dry conditions...

Thx!

I don't if this will help you but, It'll just put it out there.
A low life tried, or was successful (couldn't find anything missing or messed up inside) in getting into my 4r. Jacked outside drivers side door handle, messed up drivers side door lock.

While driving the car home, the drivers lock, and sometimes all the locks would actuate up and down. Sometimes slow, sometimes very quickly. No pattern of actuation. Just randomly.

Took the panels off to take a peak, of course the usual destruction with that kind of intrusion.

But what was interesting was the wire pigtails at the end of the drivers lock. Looks like lowlife cracked the 2 clip bracket holding that clip on to the end of the lock.

I unclipped that wire lead going into the harness and the actuation stopped.

Got another wire lead from the pick and pull $3 and all is fine now. Toyota wanted $70 for that wire at the time.

So damage to connectors can cause these actuators to act up.

Maybe the OP has a cracked or fractured connector in the door.

Good to know...

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It's a simple 2 wire. Easily to troubleshoot by just unplugging the wire terminal and see if it solves the ghost actuating.

Thanks. I'll look into that pigtail. What's so strange though is the intermittent nature of it all. It's been fine for the last week - waiting for it to rear its ugly head again, and will then dig back into the door to catch it in the act. LOL.

This is the best route. Go to your local pick and pull and tear open the lock system in the same sub-generation year as your 4Runner which would be 99-00. Or at least a 96-00. Since you don't have to put the junkyard 4Runner back together, use this opportunity to learn the system and the wiring routes then take everything relevant to your issue. Wire leads, pushrods, anything you think might help. Taking the fuse box (junction box) might help as we IF THE PART NUMBERS MATCH! Photos of yours helps to compare as plugs and wiring changed over the years. You'll pay much less than new and the chances of the junkyard 4Runner having the same issue is next to none.

Now that you've practiced on the junkyard 4Runner, install the 'new' parts into your 4Runner and see if that clears up the issue. If money is tight save the fuse box for last as those are a bit pricey depending on the yard. You can always ask for pricing. Note that removing the fuse box is a long process but can be made shorter with some wire cutters. Small hands and strong grip strength helps here.

The door lock motors also have a built-in position detection switch. If that is intermittent, the lock control system may freak out. Water can also get in through the firewall grommet in the back driver's side corner of the engine bay and get down on to the back of the fuse box + body ECU there... so, they are both possibilities.

-Charlie

Since it started with rain, could it be that water got into a door switch or two? If so, could the switch(es) have corroded over time with frequent moisture inside? Maybe there's still moisture. If you're able to reliably duplicate the problem, maybe disconnect all the door switches and see if it goes away. If so, reconnect one at a time. OR, start with disconnecting the driver door switch only, then another if not fixed, etc. Just a thought.